8/12/2019 1993_Alpern_etal_1993

1/7

Org. Geochem.Vo l. 20, No. 6 pp. 789-795, 1993 0146-6380/93 6.00 + 0.00Printed in Great Britain. All rights reserved Copyright 1993 Pergamon Press Ltd

e t e c t i o n a n d e v a l u a t i o n o f h y d r o c a r b o n s i n s o u r c e r o c k sb y f l u o r e s c e n c e m i c r o s c o p y

B. ALPERN,1'2 M . J. LEMOS DE SOUSA, H . J. PINHEIRO a nd X . ZH U3.'23 bis, rue des Cordelitres, 75013 Paris, France, 2Organic Petrology Unit, Department of Geology, Fac ultyof Sciences , Univers i ty of Porto, Praga Gom es Teixeira , 4000 Porto, Portug al and 3Centra l Labora toryof Petroleum G eology, P.O. Box 916 , 214151 Wuxi , Peop le 's Repub l ic of ChinaA bstr act --In pursuing the detect ion of hydrocarbon s in sedimentary rocks by convent ional p etrologicalmetho ds , an a t tem pt has been m ade to corre la te s tandard f luorescence param eters with the qual i ty andquant i ty of hydrocarbons present in crushed rocks embedded in epoxy res in. The capaci ty of theembedding res in, com mon ly used in the p repara t io n of petrographic samples , to extract and p hys ical lyfix hydro carbon s is recognized. This phenomenon perm its one to measure mon ochrom atic fluorescenceparam eters , 1 546 and Q (u.v. ) 650/500, on the t rappe d hydroca rbons and to corre la te these parameterswith selected geochemical data.The potent ia l app l ica t ion of us ing these petrological parameters to evaluate oi l quant it ies and qual it iesis tested using real case studies. It is also shown that it is possible to directly detect the mature zone ineach case.Key words crude oi l , epoxy res in, f luorescence, geochemis try, hydrocarbon, matura t ion, petrology,reservoir, source rock

INTRODUCTIONO i l is n o r m a l l y p r e s e n t i n s o u r c e r o c k s h a v i n g e n t e r e dt h e m a t u r a t i o n z o n e ( o i l w i n d o w ) . H o w e v e r , i t i s a l s of o u n d i n o t h e r s e d i m e n t a r y r o c k s d u e t o i t s m i g r a t i o n .I n t h i s s t u d y , n o v e l p e t r o g r a p h i c t e c h n i q u e s a r e u s e dt o i d e n t i f y s u c h o c c u r r e n c e s o f o i l .

F l u o r e s c e n c e p r o p e r t i e s o f h y d r o c a r b o n s h a v e b e e ni n v e s t i g a t e d b y m a n y a u t h o r s , v i z. O t t e n j a n n ( 1 98 0 ),B e r t r a n d et al . ( 1 9 8 6 ) , H a g e m a n n a n d H o l l e r b a c h( 1 9 8 6 ) , M a r t i n e z a n d C o n n a n ( 1 9 8 9 ) . I t h a s b e e ne s t a b l i s h e d c l e a r l y t h a t t h e f l u o r e s c e n c e o f h y d r o -c a r b o n s i s r e l a t e d to t h e d i s t r i b u t i o n o f n e l e c t r o n s ina r o m a t i c r i n g s a n d c o n j u g a t e d d o u b l e b o n d s . D u r i n gu . v . e x c i t a t io n n e l e c t r o n s a r e e x c i t e d f r o m o n e o r b i t a lt o t h e o t h e r , a n d u p o n r e t u r n i n g t o t h e i r g r o u n ds t a te , e m i t p h o t o n s ( r a d i a t i o n ) i n t h e v i s i b le s p e c t r u m( L i n a n d D a v i s , 1 9 8 8 ) .

I n t h e p r e s e n t i n v e s t i g a t i o n a n a t t e m p t h a s b e e nm a d e t o e s t a b l i s h r e l a t i o n s b e t w e e n f l u o r e s c e n c ep a r a m e t e r s a n d o i l q u a l i t i e s ( i n t e r m s o f c h e m i c a lc o m p o s i t i o n ) a n d q u a n t i t i e s , b e a r i n g i n m i n d t h a t t h em e t h o d o l o g y e m p l o y e d d i f fe r s f r o m o t h e r s in t h a t i ta t t e m p t s t o p r o f i t f r o m t h e f o l l o w i n g : ( 1 ) r e c o g n i t i o nt h a t h y d r o c a r b o n s a r e e x t r a c t e d a n d t r a p p e d b y t h ee p o x y r e s in i n w h i c h r o c k s a r e e m b e d d e d , (2 ) h y d r o -c a r b o n s b e c o m e d e t e c t a b l e b y f l u o r e sc e n c e e x c it a t i o n ,a n d ( 3 ) t h e m o n o c h r o m a t i c m e a s u r e m e n t s c a n b ec a r r i e d o u t b y r o u t i n e m e t h o d s a n d e q u i p m e n t s i m i la rt o t h o s e u s e d f o r v i t r i n i t e r e f l e c t a n c e .

*Present address : Organic Petrology Unit , Department ofGeo logy, Facu l ty of Sciences , Univers i ty of Po rto, PraqaGomes Teixeira , 4000 Porto, Portugal .tT h i s epoxy re s in -ha rdne r k i t i s s upp l i ed by ST RUE RS.

N e v e r t h e l e s s, o u r c o n c e r n i s p r e s e n t ly n o t d i r e c t e da t e c o n o m i c a s p e c t s o f o i l f i e l d s , b u t i n s t e a d a tt h e r e l e v an c e o f m i c r o - i m p r e g n a t i o n s o r m i c r o -n e o g e n e r a t i o n s d e t e c t e d b y o p t i c a l m i c r o s c o p y w h i c hm a y b e a p p l i e d t o p e t r o l e u m p r o s p e c t i n g .

METHODOLOGYS a m p l e p r e p a r a t i o n

M o s t o f t h e s a m p l e s s t u d i e d w e r e w h o l e r o c kc u t t i n g s a l r e a d y in a g r a n u l a r f o r m . M i l d c r u s h i n g( < 2 m m ) w a s o n l y n e c e s sa r y w h e n t h e s i ze w a s t o ob i g o r i r r e g u l a r . T h e c u t t i n g s w e r e w a s h e d , d r i e d ,a n d v i s ib l e c o n t a m i n a t i o n s w e r e r e m o v e d . T h e c l e a ng r a n u l a r s a m p l e s o f w h o l e r o c k s w e r e t h e n e m b e d d e di n a n e p o x y re s in ( E P O F I X t ) a n d p o l i s h e d a cc o r d i n gt o r o u t i n e p e t r o g r a p h i c m e t h o d s ( p o l i s h e d b l o c k s ) .T h e e p o x y r e s in b e h a v e s a s a n e x t r a c t o r o f h y d r o -c a r b o n s , f a v o u r i n g a p h y s i c a l r e a d j u s t m e n t o f t h i sf l u i d p h a s e i n t o t h e e m b e d d i n g r e s i n i t s e l f , w i t h o u ta c h e m i c a l r e a c t i o n . I n a d d i t i o n , crude oi l s a m p l e sw e r e m o u n t e d o n a s l i d e ( s in g l e d r o p ) a n d c o v e r e dw i t h a l a m e l l a ( c o v e r s l ip ) . I n s o m e c a s e s , e a c h o i l w a sm i x e d w i t h e m b e d d i n g r e s in i n v a r i o u s p r o p o r t i o n s( 0 . 5 - 4 . 0 % ) s o t h a t t h e i r p r o p e r t i e s , i n s u c h a ne m b e d d i n g m e d i u m , c o u l d b e s t u d i e d . W i t h r e f e r en c et o t h e l a t t e r p o i n t , o t h e r e m b e d d i n g r e s in s w e r e a ls ot e s t e d a n d p r o d u c e d s i m i l a r r e s u l t s .H y d r o c a r b o n s

O n m i x i n g t h e r o c k s a m p l e s w i t h t h e e p o x y r e s i n ,t h e h y d r o c a r b o n s w h i c h m a y b e p r e s e n t in t h e r o c kp a r t i c l e s a r e p a r t l y e x t r a c t e d a n d e a s i l y d e t e c t e du n d e r f l u o re s c e nc e . S i n c e t h e e m b e d d i n g r e s in i s v e r yl o w f l u o r e s c i n g ( I 5 4 6 = 6 % ) , a n d o n c e i t i s m i x e d

OG 20/6 L 78 9

8/12/2019 1993_Alpern_etal_1993

2/7

790 B . A L P E R N e t a lT a b l e 1 . C l a s s i f i c a ti o n o f h y d r o c a r b o n s ( H C ) p r e s e n t i n r o c k s c r u s h e d a n d e m b e d d e d i n e p o x y r e s in , a s o b s e r v e du n d e r f l u o r e s c e n c e a n d re feren e to m e a s u r e m e n t s

utomomhH C

dro~f i nwcsud~ oonmlax)non-ephed~ HO

m e e ~ r e m e n t s

O 8 5 0 / 5 0 0

n o tm e u u r e d

d lm m l v e d H C I n r u l n i 1 5 4 6 a n df o = o 5 o ot

w i t h a s a m p l e c o n t a i n i n g h y d r o c a r b o n s , t h e re s u l ti n gf l u o re s c e n c e p r o p e r t i e s a r e t a k e n t o b e t h o s e f r o m t h eh y d r o c a r b o n s t h e m s e l v e s .

A p o r t i o n o f th e h y d r o c a r b o n s a p p e a r a s automorphh y d r o c a r b o n s , w h i l s t a n o t h e r p o r t i o n i s dissolvedo r m i x e d w i t h th e e m b e d d i n g e p o x y r e s in T a b l e 1 ).T h e s e c a t e g o r i e s h a v e b e e n d e s c r i b e d a n d i l l u s t ra t e di n d e t a i l b y A l p e r n et al. 1 9 9 2 ). A s a b r i e f s u m m a r y ,a u t o m o r p h h y d r o c a r b o n s a r e c a t e g o r i z e d a s d r o p sa n d f il m s ; d r o p s a r e c l e a r l y s p h e r i c a l i n f o r m a n dv a r i a b l e i n s i z e . T h e i r c o l o r r a n g e s f r o m g r e e n t oy e l l o w - b r o w n . F i l m s a p p e a r a s c o a t i n g s o f, o r s t u c k t op a r t i c l e s a n d w i t h v a r y i n g t h i c k n e s s . T h e i r f l u o re s c e n c ec o l o r a l s o v a r ie s f r o m g r e e n t o y e l l o w - b r o w n . O n t h eo t h e r h a n d , t h e d i s s o lv e d h y d r o c a r b o n s c a t e g o r y i sc o m p r i s e d o f t h o s e w h i c h m i x w i t h t h e e m b e d d i n ge p o x y r e s i n g i v i n g i t a f l u o r e s c e n c e c o l o r a l s od e p e n d e n t o n t h e i r c h e m i c a l c o m p o s i t i o n : g r e e n i s hf o r s a t u r a t e d o i l s a n d y e l l o w f o r t h e a r o m a t i c o n e s .Optical analysis

T h e p e t r o g r a p h i c e q u i p m e n t u s e d f o r t h e f l u o r -e s c en c e m e a s u r e m e n t s i s c o m p r i s e d o f a L e i t z m i c r o -s c o p e M P V C o m b i ) w i t h r e f le c t a n c e a n d f l u o r e sc e n c ea t t a c h m e n t s . U l t r a v i o l e t f l u o re s c e n ce c o n d i t i o n s w e r eo b t a i n e d w i t h a H B O 1 00 W m e r c u r y l a m p , a n U G Ie x c i t a t i o n f i l t e r I = 36 5 n m ) , a K 4 3 0 b a r r i e r f i lt e ra n d a T K 4 0 0 d i c h r o i c m i r r o r . T h e i n t e n s i t y o f t h ee m b e d d i n g e p o x y r e s in w a s m e a s u r e d a t I = 5 46 n m ,u s i n g a n u r a n y l - g l a s s a s a s t a n d a r d . T h e s iz e o f t h ef ie l d m e a s u r e d o n t h e e m b e d d i n g r e s in w a s 1 0 0 /~ m 2,a n d a m i n i m u m o f 5 0 m e a s u r e m e n t s w e re r e c o r d e df o r e a c h s a m p l e . A l t h o u g h t h e r a t i o o f Q = 6 5 0 / 50 0i n u . v . l i g h t m a y b e m e a s u r e d b o t h f o r t h e h y d r o -c a r b o n s f il m s , d r o p s ) , w h e n p r e s en t , a n d f o r t h ee m b e d d i n g r e s in , i n t h e p r e s e n t s t u d y i t w a s o n l y d o n eo n t h e e p o x y e m b e d d i n g r es in . T h e a b o v e m e a s u r e -m e n t s w e r e c a r r i e d o u t u s i n g a 5 0 x o i l i m m e r s i o no b j e c t i v e , a n d t h e s p e c t r a l f l u o r e s c e n c e o f t h e f r e ec r u d e o i l s w e re p e r f o r m e d u s i n g w a t e r i m m e r s i o n .

A P P L I C A T I O N S T O P E T R O L E U M P R O S P E C T I N GCorrelation of Q u.v.)650/500 with oil quality

Q u . v .) 6 5 0 / 5 0 0 m e a s u r e m e n t s w e r e c a r r i e d o u t o n1 0 s e l e c t e d o i l s w h i c h r e p o r t e d w i d e v a r i a t i o n s i nc h e m i c a l c o m p o s i t i o n T a b l e 2 ).

A g o o d p o s i t iv e c o r r e l a t i o n w a s o b t a i n e d b e t w e e nQ u . v. )6 5 0 / 50 0 a n d t h e p e r c e n t a g e o f a ro m a t i c sA R O ) p l u s h e a v y p r o d u c t s H P = r e s in s + a s p h a l t -

e n e s ) F i g . 1 ). T h a t i s t o s a y t h a t a r o m a t i c o i l s a r em o r e r e d s h i f t e d t h a n s a t u r a t e d o i l s . T h i s w a s c o n -f i r m e d b y s p e c t r a l f l u o r e s c e n c e m e a s u r e m e n t s u s i n ga w a t e r i m m e r s i o n o b j e c t i v e ) t h a t s h o w e d a r o m a t i co i ls h a d 2 m a x v a l u e s a t l o n g e r w a v e l e n g t h s th a ns a t u r a t e d o i l s e . g ., F i g . 2 ).

S i n ce o u r r o u t i n e m e t h o d s a r e c a rr i e d o u t o n r o c ks a m p l e s e m b e d d e d i n e p o x y r e si n , t h e c r u d e o i l s w e r em i x e d w i t h r e si n a n d f l u o re s c e n c e m e a s u r e m e n t s w e r ep e r f o r m e d . T h e r e s u l t i n g c o r r e l a t i o n b e t w e e n t h ec o l o r , e x p r e s s e d b y Q , a n d q u a l i t y , a s S A T / A R O+ H P ) , r e m a i n e x c e l l e n t w i t h r = - 0 . 9 5 7 F i g . 3 ). I ts h o u l d b e n o t e d t h a t , f o r e a c h c r u d e o i l , t h e Q v a l u e so b t a i n e d o n e a c h o f t h e d i ff e re n t c o n c e n t r a t i o n s o fo i l m i x e d w i t h t h e e p o x y r e s i n , w e r e s o s i m i l a r t h a tt h e a v e r a g e Q v a l u e w a s c o n s i d e r e d r e p r e s e n t a t i v e .T h i s l a s t p o i n t w a s a v a l i d a rg u m e n t i n f a v o u r o f

T a b l e 2 . T h e g e n e t i c n a t u r e a n d c h e m i c a l c o m p o s i t i o n o f t e nc r u d e o i l sR e s i n s +

G e n e t i c S a t u r a t e d A r o m a t i c a s p h a lt e n e sO i l N o . c h a r a c t e r ( ) ( ) ( ) D e n s i t y

1 M a r i n e 8 2 . 0 1 4 . 0 4 . 0 0 . 8 12 C o n t i n e n t a l 8 4 . 9 1 2 . 9 2 . 2 0 . 8 73 M a r i n e 2 6 . 7 5 6 . 3 1 6 . 9 0 . 9 74 M a r i n e 5 8 . 8 2 9 . 0 1 0 .8 0 . 9 35 M a r i n e 8 8 . 5 l 1 .5 - - 0 . 7 96 M a r i n e 6 3 . 0 3 3 . 1 3 . 9 0 .8 17 M a r i n e 4 2 . 0 2 7 . 0 3 1 . 0 0 . 9 08 M a r i n e 2 8 . 0 4 7 . 0 2 5 . 0 0 . 8 79 M a r i n e 6 3 . 3 2 9 . 3 7 . 4 0 . 8 0l 0 M a r i n e 6 0 . 0 2 2 . 0 1 8 .0 0 . 8 3

8/12/2019 1993_Alpern_etal_1993

3/7

Hydrocarbon detection and evaluation by fluorescence microscopy 791 .0 - - Ln (O) = - 5 .5 3 + 1 .242 Ln (ARO +HP ) /0 .8 - - N = 10, r = 0 . 9 5 1 + 7 ~ A ro m a tic

O

0 , 6 - -u-~c~ 9 ~ + 8

0.4 - +> + 1 0

+ ~ e d k 6. 2 - + 2

t0 20 40 60 80 100

A R O + H P ( % )F i g . 1 . C o r r e l a t i o n b e t w e e n o p t i c a l p a r a m e t e r Q ( U V ) o n f r e e o il (s l id e ) a n d o i l q u a l it y ( A R O + H P % )fo r 10 se lec ted o i l s .

100

5

0 I I I I I I I I I I I I I I400 500

100

5

W a v e l e n g t h ( n m )I I I I | I I I600 700

o . . ,/

0 400

C r u d e o i l N o 5S A T U R A T E D~ . M A X Q 6 5 0 S A T //500 (ARO+HP)ZU12 440 0 .05 7 .62ZU I3 440 0 .04 7 .62ZU 14 440 0 .04 7 .62ZU15 440 0 .03 7 .62ZU 16 430 0 .04 7 .62

M e a n 4 3 8 0 0 4 7 6 2

~ Z U 12 Z U 1 3 - - Z U 1 4ZU15 ZU16 M ean

f XI I I I I I I I I I I I I500 600 700W a v e l e n g t h ( n m )

F i g . 2 . S p e c t r a l f l u o r e s c e n c e o f N o . 5 a n d N o , 3 fr e e o i l s a m p l e s .

C r u d e o i l N o 3A R O M A T I C

k M A X Q 6 5 0 S A T //500 (ARO+HP)ZU I 560 1 ,06 0 .36ZU2 580 0.99 0.36ZU3 560 0.96 0.36ZU 4 580 1 .02 0 .36ZU5 580 1.03 0.36Mean 572 1.01 0,36

- - - ~ Z U 1 Z U 2 Z U 3 [.. . .. . . ZU 4 .. .. . ZU6 Mean

8/12/2019 1993_Alpern_etal_1993

4/7

792 B. ALPERNet al.1 . 0 m Q ( o i l i n r e s i n ) = 0 . 2 4 4 - 0 . 0 3 1 ' ( S A T / ( A R O + H P ) )

N = 1 0 , r = - 0 . 9 5 7

..= 0.8r e d

& 0 . 6 -~ 0 . 4 - - A r o m a t i c> 3 7 + 4~ - , I ~ ~0 2 1 8 1 0 ~ ' 9 1 . . . . . . . . . . . . ~

~ ~ 2 S a t u r a t e d| b Z u e I I I - - ' ~ , I I

0 2 4 6 8 1 0S A T / ( A R O + H P )

Fig. 3. Correlation between Q (UV) of embedding epoxy resin mix ed with 1 oil (polished block) andoil quality [SA T/(ARO + H P)].

c o n s i d e r i n g Q a s a n o p t i c a l p a r a m e t e r g r o s s l y r e l at e dt o o i l q u a l i t y ( A l p e r n et al . 1992).Corre la t i on o f 1546 wi th o i l quan t i t y

As p rev ious ly men t ioned t he f l uo rescence p rope r t i e so f o i ls a r e p r e d o m i n a n t l y r e l a t e d t o a r o m a t i c s t r u c -tu re s . The re fo re , on ly w hen the qua l i t y , i .e ., r e l a t ivep e r c e n t a g e o f a r o m a t i c h y d r o c a r b o n s i n a n o i l, isk n o w n ( Q v a l u e ) c a n t h e f l u o re s c e n c e in t e n s it y ( I 5 4 6 )be r e l a t ed t o o i l quan t i t y . Th i s f a c t was e s t ab l i shedf r o m t h e s a m p l e s p r e p a r e d b y m i x i n g i n c r e a s i n gq u a n t it i es o f e a c h o i l ( 0 . 5 - 4 . 0 ) w i th e p o x y r es in a n dmeasur ing t he i r r e spec t i ve f l uo re scence i n t ens i t i e s .

I t i s c l e a r f rom Fig . 4 t ha t i f t he qua l i t y i s f i xed ,fo r exa mp le Q (u .v . ) equa l t o 0 .4 , t he 1 546 va lue i sq u a n t i t y d e p e n d a n t . I t m a y e f f ec t iv e ly b e o b s e r v e dtha t 1 546 i nc rea se s f rom 200 to 450 wi th an i nc rea sei n o i l p r o p o r t i o n ( c o n c e n t r a t i o n ) f r o m 0 .5 to 4 . 0 .

S i n ce it is s u s p e c t ed t h a t b o t h 1 5 4 6 a n d Q 6 5 0 / 5 0 0m a y s i m u l t a n e o u s l y i n f l u e n c e q u a l i t y a n d q u a n t i t y ,fu tu re i nves t i ga t i ons a re p re sen t ly be ing d i r ec t ed a te s t a b l i s h i n g t h e m a t h e m a t i c a l c o r r e l a t i o n s b e t w e e nt h e s e f o u r p a r a m e t e r s .Est imat ion o f o il quan t it i e s i n pe t ro l eum boreho le s

T h e m o s t f r e q u e n t p a r a m e t e r s u s e d t o e s t i m a t eo i l quan t i t i e s i n bo reho le a re t he we igh t pe rcen to f e x t ra c t a b l e o r g a n i c m a t t e r a n d t h e S 1 y i el d f r o mR o c k E v a l . H o w e v e r , w e b e l i e v e t h a t t h e e x t r a c t i o nc a p a c i t y o f th e e m b e d d i n g e p o x y r e s i n is e q u a l o rm a y b e e ve n g r e at e r t h a n t h a t o f t h e a b o v e m e n t i o n e dp a r a m e t e r s , b e c a u s e i n p r e v i o u s l y e x t r a c t e d sample s ,t h e f l u o r es c e n c e i n te n s i ty ( I 5 4 6 ) o f t h e e m b e d d i n gre s in can s t il l r ema in s ign i f ic an t . The r ea son s fo r t h i sa r e t h o u g h t t o b e r e l a t e d w i t h t h e f o l l o w i n g t h r e easpects (Table 3) :4 5

4 0 0 - - 4 . 0 4o J5 0 - -~ - 3 0 0 - , , ,3 0 v / ' ~ i / /.-- . / / / 1 . 0 % 0 . 5 %

o_2 0 0 % : N = 7 , r = 0 . 9 0 7 , 1 = - 2 9 . 3 7 + 5 6 8 . 2 6 * Q1 5 0 1 0 ~ : ~ = 7 , r = 0 9 0 0 , , = - 3 1 4 2 + 7 0 6 4 6 0

~ ~ / / / / / 2 . o % : ~ = 7 , r = 0 . 9 0 2 , , - 4 6 . 9 1 .,- 9 7 6 . 0 8 0~ 1 0 0 3 . 0 ~ : ~ = 7 , r = 0 9 1 5 , ~ = - 4 4 7 8 + 1 1 O 83 5 0- 5 o / / / / j r = 09 3 8,,= -4 0 09 1 21 5 45 .0

/ f / I I I I I I I I I0 0 . 1 0 . 2 0 . 3 0 . 4 0 . 5 0 . 6 0 . 7 0 . 8 0 . 9 1 . 0

Q ( U V ) [ o i l in r e s i n ]Fig. 4. Correlation between optical parameters [Q (U V) and I 546 (UV)], oil qualit ies and increasingpercentages (0.5 ~.0 ) of oil mixed with embedding epoxy resin (polished blocks). If the quali ty is fixed,then 1 546 is proportional to hydrocarb on percent.

8/12/2019 1993_Alpern_etal_1993

5/7

H y d r o c a r b o n d e t e c t i o n a n d e v a l u a t i o n b y f l u o re s c e n ce m i c r o s c o p yT a b l e 3 . C o m p a r i s o n b e t w e e n t h e e x t r a c t i o n c a p a c i ty o f t h e e m b e d d i n g e p o x y r e s i n a n d g e o c h e m i c a l t o o l s ( a ft e rEs p i t a l i 6 e t a l . 1 9 85 , m o d i f ie d ) . T h e s h a d e d a r e a c o r r e s p o n d s t o t h e H C o p t i c a l l y d e t e c t e d

7 9 3

E X l l M ~ I K J EOI NI AI ~ NATlrlER

IqOGK EV LPAIqAMETIIm

CHLO f t OFOl m EXTR CTmnJulm)

EXllU,~lON BYEMIDEDONm RESIN

H Y D R O C R B O N O H E W C O MP QU N DeC a r b o n n u m b e r

, i I ~ I g i * i J , , i ~ I t , i c , o *

IO 8 1 1 ~i

R e u l n eo p h m l t e n e a

I~ l a o l o

( 1 ) I t i s k n o w n t h a t t h e S I y i e l d d o e s n o t c o r r e -s p o n d t o t h e t o t a l f r e e h y d r o c a r b o n s i n r o c k s ,bu t on ly t o t he vo l a t i l e f r ac t i on , t yp i ca l l yc o n t a i n i n g < 3 3 c a r b o n s .

(2 ) G as bubb le s , pe rha ps be long ing to SO, a re o f t eni n c l u d e d i n o i l d r o p s v i s i b l y t r a p p e d i n t h ee m b e d d i n g e p o x y r e s i n .

( 3 ) T h e f a c t t h a t t h e C 3 3 + f r a c t i o n i s i n c l u d e din t he $2 y i e ld and no t i n t he SI y i e ld , exp l a insthe ex i s t i ng cor re l a t i ons be tween 1 546 and $2(Fig . 6 ) . Th i s i s so because t he embeddinge p o x y r e s i n i s c a p a b l e o f s e p a r a t i n g a n d f i x i n ga t l ea s t a pa r t o f t he C33 + f rac t i on .

In t e s t i ng t he app l i ca t i on o f the rou t ine f l uore scencepa rame te r s , t h ree rea l ca se s tud i e s a re p re sen t ed . Inb o r e h o l e C A I ( F i g . 5 ) t h e c o r r e l a t i o n b e t w e e n 1 5 4 6and S1 i s exce l l en t wi th r = 0 .934 . In boreho le TC(Fig . 6 ) t he cor re l a t i on i s a l i t t l e l ower , r = 0 .89 , bu tthe va r i a t i ons wi th dep th a re ve ry s imi l a r be tween I5 4 6 a n d t h e R o c k E v a l y i e ld d a t a . I n t h e P a r i s b a s i n(Fig . 7 ) , Toa rc i an o i l sha l e s a re c l ea r ly de t ec t edand the cor re l a t i on be tween 1 546 and se l ec t ed geo-chem ica l da t a i s aga in v e ry h igh ( r - - 0 .954). Th ea b o v e e x a m p l e s i n f e r t h a t w i t h i n a g i v e n s e c t i o nthe o i l qua l i t y seems to be re l a t i ve ly con s t an t s i nce thec o r r e l a t io n s b e tw e e n 5 4 6 a n d g e o c h e m i c a l d a t a a r er a t h e r g o o d .

1 0 0 - -

~ 8 0 - -

6 0 - -

, . - , 40>- 2 0

~

L n 1 5 4 6 = 2 . 5 7 + 0 . 4 9 * L n $ 1N = 12 , r = 0 . 934

,+/i i0 1 0 2 0 3 0 4 0 5 0

S 1 ( % w t )F i g . 5 . B o r e h o l c C A 1 : c o r r e l a t i o n b e t w e e n 1 5 4 6 o f th e w h o l e r o c k ( W R ) e m b e d d i n g e p o x y r e s i n (p o l i s h e d

b l o c k ) a n d S 1 f r o m R o c k E v a l .

8/12/2019 1993_Alpern_etal_1993

6/7

~&

1 0 0 0 S1 $2 $1 + $2 I 546 (UV)1500 --

2000 - -

2500

3000

3500

794 B. ALPERN e t a l

I I I i J10 20 30 40 50S ( x ) ( m g / g ) v a l u e s f r o m R o c k E v a l a n df lu o r e s c e n c e in te n s i ty ( 1 5 4 6 ( UV ) (%) )

Fig . 6 . Borehole TC: a n exam ple of the re la t ion be tween selected R ock Eva l geochemica l da ta (S1 and$2) and emb edding epoxy res in f luorescence in tens i ty [ I 546 (UV)]. In th is case the cor re la t ion coeff ic ien tbetween 1 546 and S1 is 0.89.

CONCLUSIONSL i q u i d h y d r o c a r b o n s o c c u r f r e q u e n t l y i n s e d i -

m e n t a r y r o c k s . T h e y m a y b e t r a p p e d a n d f i x ed in t h ee m b e d d i n g r e s i n d u r i n g r o u t i n e p e t r o g r a p h i c s a m p l ep r e p a r a t i o n . T h e s e h y d r o c a r b o n s m a y b e r e v e a le db y f l u o r e s c e n c e e x c i t a t i o n o f p o l i s h e d r e s in p l u g s ,a n d c h a r a c t e ri z e d b y t w o s i m p l e fl u o re s c e nc e m o n o -c h r o m a t i c p a r a m e t e r s [ I 5 4 6 a n d Q ( u . v .) 6 5 0 n m /5 0 0 n m ] . T h e y p r o v i d e i n f o r m a t i o n w i t h r e s p e c t t ot h e o i l q u a n t i t i e s a n d q u a l i t i e s ( in t e r m s o f c h e m i c a lc o m p o s i t i o n ) o f t h e r o c k . Q , e x p r e s s i n g t h e f l u o r -e s c e n c e c o l o r , i s m o r e r e l a t e d t o t h e o i l q u a l i t y a n dt h e c o r re l a t i o n w i t h t h e p r o p o r t i o n o f a r o m a t i c h y d r o -

c a r b o n s i s g o o d . I n b o r e h o l e c a s e s t u d ie s 1 5 4 6 s h o w sa l s o g o o d c o r r e l a t i o n s w i t h S 1 y i el d f r o m R o c k E v a l .

T h e s i m p l e p r o c e d u r e s f o l l o w e d i n o u r i n v e s t i g a -t i o n n o t o n l y p e r m i t e v a l u a t i o n s o f o i l q u a l i t i e s a n dq u a n t i f i e s , b u t c a n a l s o d e t e c t t h e r m a l l y m a t u r e z o n e s .T h u s , t h e h y d r o c a r b o n f l u o r e s c e n c e p r o p e r t i e s o fe p o x y e m b e d d e d r o c k s p r o v i d e a n a l t e rn a t i v e m a t u r -a t i o n p a r a m e t e r w h i c h s u p p l e m e n t s c o n v e n t i o n a l i n -d i r e c t m e t h o d s s u c h a s s p o r e c o l o r a t i o n , v i t r i n i t er e fl e c ti v i ty , T h e r m a l A l t e r a t i o n I n d e x ( T A I ) , e t c .

A l t h o u g h o u r i n v e s t i g a t i o n p r o v i d e s a d i r e c tm e t h o d o f d e t e c ti n g m a t u r e z o n e s i t is st il l n e c e s s a r yt o d i s t i n g u i s h s o u r c e r o c k s f r o m r e s e rv o i r s . T h e l a t t e ri s a c c o m p l i s h e d b y c a r e f u l m i c r o s c o p i c o b s e r v a t i o n s .

I 5 4 6 ( UV) [ e mb e d d in g r e s in ]40 50 60 70 80 902000 I I I I I

2200Toarcian 2383

2426 ~ 2400Pliensbachian 2566 &Sinemurian 2573 r~ 2600Hettangian 2738

2800

100

_ 1 546 S1/TO C I 546 = 19.65 + 49.95* (S1/TOC )N = 8 , r = 0 .9 5 4

3000 I I I0.3 0.6 0.9 1.2 1.5s 1 ( r a g / g ) / T O C ( % w t )

Fig . 7 . Var ia t ions w ith depth a nd c or re la t ion be tween op t ica l [ I 546 (UV)] and geo chemica l parameter s(S1/TOC) for the Par is Bas in .

8/12/2019 1993_Alpern_etal_1993

7/7

H y d ro c a rb o n d e te c t io n a n d e v a lu a t io n b y f lu ore s ce n c e m ic ro s c o p y 795A c k n o w le d g e m e n t s - -T h e a u th o r s a re in d e b te d to C h e v ro nO v e rs e as P e t ro l e u m In c . , T o ta l , In s t i t u t F ra n q a i s d u P t t ro l e- - I F P , a n d G a b in e te p a ra a P e s q u i s a e E x p lo ra ~ f io d eP e t rb l e o - - -G P E P fo r s u p p ly in g b o re h o le c u t t in g s, o i l s a n dg e o c h e m ic a l d a t a , a n d fo r p e rm is s io n to p u b l i s h c o r re -s p o n d in g in fo rm a t io n . In p a r t i c u la r , Mr G . D e m a i s o n a n dMis s M. R . C a s s a C h e v ro n ) , M r J .-L . O u d in T o ta l ) , Ms s r sB. Du rand and J . Esp ita li6 IFP) , and Mssrs J . Agn e loF e rn a n d e s , R . V ie i r a, a n d F . L a im a G P E P ) a re a c k n o w l -edged fo r the ass is tance p rov ided during th is inves t iga t ion .L a s t ly , w e a re m o s t g ra t e fu l t o Mrs M. Ma rq u e s fo r h e rsupport and adv ice on compute r g raph ic des ign .

R E F E R E N E S

Alpern B. , Lemos de Sousa M. J . , P inhe iro H. J . andZ h u X . 1 9 92 ) O p t i c a l m o rp h o lo g y o f h y d ro c a rb o n sa n d o i l p ro g e n ito r s i n s e d im e n tary ro c k s - - r e l a t io n s w i thg e o c h e m ic a l p a ra m e te r s . Publ. Mus. Labor. miner geol.Fac. Ci~ nc. Porto N.S., 3 , 1-21, Pls 1-15.Bert rand P . , P i t t ion J . -L . and Bernau d C. 1986) F luo r-escence o f sed imenta ry o rgan ic mat te r in re la t ion to i ts

c h e m ic a l c o m p o s i t io n . In Advances in Organic Geochem-istry 1985 Edited by Ley thaeuse r D. and Rul lk6 t te r J . ) .Org. Geochem. 10, 641-647.Esp ita li6 J . , D ero o G. and M arqu i s F . 1985) Ro ck Eva lpyrolysis and its applications. Institut Fr an ci s du Pttro le .Report re f . 33578 . )H a g e m a n n H . V . a n d H o l l e rb a c h A . 1 9 86 ) T h e f lu o r-escence behav iour o f c rude o i ls wi th respec t to the irth e rm a l m a tu ra t io n a n d d e g ra d a t io n . In Advances inOrganic Geochem istry 1985 Edited by Ley thaeuse r D.and Rul lk6 t te r J . ) . Org. Geochem. 10 , 473-480 .L in R . a n d D a v i s A . 1 9 88 ) A f lu o ro g eo c h e m ic a l m o d e lfo r coa l macera ls . Org. Geochem. 12, 363-374.Ma r t in e z L . a n d C o n n a n J . 1 9 89 ) A p p ro c h e d e la m ig ra t io nprimaire des hydrocarbures pa r des 6 tudes in t6gr6es deg6och imie e t de p6 tro log ie o rgan ique sur roches m6reschauf6es in vitro. In P . Bert rand , Organ isa t . , Co l loq . ,Appl ica t ions de la P6 tro log ie Organ ique en G6olog ie ,Orl6ans, 1988. Bull. Soc. gd ol. Ft. 8 S6r. , 5 , 5: 937-950.O t t e n ja n n K . 1 9 80 ) S p e k tra l e F lu o re s z e n z -Mik ro p h o to -metr ic yon Kohlen und Olsch ie fe rn . Lei tz -Mit t . Wiss .Techn . Wetz lar VIII 8, 262-272.